Backport PR #51470 on branch 2.0.x (DEPS: Partial Matplotlib 3.7 supp…

…ort) (#51510)

Backport PR #51470: DEPS: Partial Matplotlib 3.7 support

Co-authored-by: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Co-authored-by: Patrick Hoefler <61934744+phofl@users.noreply.github.com>

pandas/plotting/_matplotlib/core.py

@@ -54,6 +54,7 @@
 
 import pandas.core.common as com
 from pandas.core.frame import DataFrame
+from pandas.util.version import Version
 
 from pandas.io.formats.printing import pprint_thing
 from pandas.plotting._matplotlib import tools
@@ -784,8 +785,11 @@ def _make_legend(self) -> None:
         if not self.subplots:
             if leg is not None:
                 title = leg.get_title().get_text()
-                # Replace leg.LegendHandles because it misses marker info
-                handles = leg.legendHandles
+                # Replace leg.legend_handles because it misses marker info
+                if Version(mpl.__version__) < Version("3.7"):
+                    handles = leg.legendHandles
+                else:
+                    handles = leg.legend_handles
                 labels = [x.get_text() for x in leg.get_texts()]
 
             if self.legend:

pandas/tests/plotting/frame/test_frame_color.py

@@ -13,6 +13,7 @@
     TestPlotBase,
     _check_plot_works,
 )
+from pandas.util.version import Version
 
 
 @td.skip_if_no_mpl
@@ -639,11 +640,18 @@ def test_rcParams_bar_colors(self):
     def test_colors_of_columns_with_same_name(self):
         # ISSUE 11136 -> https://github.com/pandas-dev/pandas/issues/11136
         # Creating a DataFrame with duplicate column labels and testing colors of them.
+        import matplotlib as mpl
+
         df = DataFrame({"b": [0, 1, 0], "a": [1, 2, 3]})
         df1 = DataFrame({"a": [2, 4, 6]})
         df_concat = pd.concat([df, df1], axis=1)
         result = df_concat.plot()
-        for legend, line in zip(result.get_legend().legendHandles, result.lines):
+        legend = result.get_legend()
+        if Version(mpl.__version__) < Version("3.7"):
+            handles = legend.legendHandles
+        else:
+            handles = legend.legend_handles
+        for legend, line in zip(handles, result.lines):
             assert legend.get_color() == line.get_color()
 
     def test_invalid_colormap(self):

pandas/tests/plotting/frame/test_frame_legend.py

@@ -8,6 +8,7 @@
     date_range,
 )
 from pandas.tests.plotting.common import TestPlotBase
+from pandas.util.version import Version
 
 
 class TestFrameLegend(TestPlotBase):
@@ -19,6 +20,7 @@ class TestFrameLegend(TestPlotBase):
     )
     def test_mixed_yerr(self):
         # https://github.com/pandas-dev/pandas/issues/39522
+        import matplotlib as mpl
         from matplotlib.collections import LineCollection
         from matplotlib.lines import Line2D
 
@@ -28,20 +30,29 @@ def test_mixed_yerr(self):
         df.plot("x", "b", c="blue", yerr=None, ax=ax, label="blue")
 
         legend = ax.get_legend()
-        result_handles = legend.legendHandles
+        if Version(mpl.__version__) < Version("3.7"):
+            result_handles = legend.legendHandles
+        else:
+            result_handles = legend.legend_handles
 
         assert isinstance(result_handles[0], LineCollection)
         assert isinstance(result_handles[1], Line2D)
 
     def test_legend_false(self):
         # https://github.com/pandas-dev/pandas/issues/40044
+        import matplotlib as mpl
+
         df = DataFrame({"a": [1, 1], "b": [2, 3]})
         df2 = DataFrame({"d": [2.5, 2.5]})
 
         ax = df.plot(legend=True, color={"a": "blue", "b": "green"}, secondary_y="b")
         df2.plot(legend=True, color={"d": "red"}, ax=ax)
         legend = ax.get_legend()
-        result = [handle.get_color() for handle in legend.legendHandles]
+        if Version(mpl.__version__) < Version("3.7"):
+            handles = legend.legendHandles
+        else:
+            handles = legend.legend_handles
+        result = [handle.get_color() for handle in handles]
         expected = ["blue", "green", "red"]
         assert result == expected